writing the reconciliation systems that process millions of FPS transactions
implementing double-entry accounting that tracks card spending and settlements
designing webhook infrastructure with message signing and replay protection
building API versioning that lets us evolve without breaking customers
creating payment approval workflows that satisfy both user experience and compliance requirements

Functional programming
you've shipped production Clojure, Elixir, Erlang, Haskell, Scala, or Scheme in a professional setting, or you've built substantial personal projects that demonstrate deep functional programming experience
Fintech domain expertise
you've worked in payments, accounts, ledgers, or compliance where you've dealt with money movement, reconciliation, and regulatory requirements
Strong software fundamentals and distributed systems knowledge
you understand consistency models, idempotency, and the failure modes that actually matter in production
Experience working in product-focused, collaborative teams
you've shaped what gets built alongside PMs and designers, not just implemented specs
Comfort with startup pace and ambiguity
priorities shift, requirements evolve, and you adapt without needing perfect clarity upfront

Remote-first flexibility: Work from anywhere in the UK
Time off: 25 days’ holiday, bank holidays and a winter break (we shut down between Christmas and New Year)
Share options: Own a part of what we’re building together
Work from abroad: Up to 20 days a year
Pension: Auto-enrolment into our Penfold scheme
Insurance: Private medical with Bupa (including family cover) and life insurance with AIG
Wellbeing: 1:1 coaching and therapy session available through Oliva
Family leave: Enhanced parental leave with up to 6 months on full pay after two years’ service
AI tools: Everyone has a Claude subscription on us and access to other premium tools
Your setup: We’ll support you in creating a comfortable and effective WFH environment.

Software Engineer

Key skills